Received-SPF: pass (google.com: domain of linux-kernel+bounces-65936-linux.lists.archive=gmail.com@vger.kernel.org designates 147.75.199.223 as permitted sender) client-ip=147.75.199.223;
Precedence: bulk
MIME-Version: 1.0
References: <20240212213922.783301-1-surenb@google.com> <4f24986587b53be3f9ece187a3105774eb27c12f.camel@linux.intel.com>
 <CAJuCfpGnnsMFu-2i6-d=n1N89Z3cByN4N1txpTv+vcWSBrC2eg@mail.gmail.com> <Zc0f7u5yCq-Iwh3A@google.com>
In-Reply-To: <Zc0f7u5yCq-Iwh3A@google.com>
From: Suren Baghdasaryan <surenb@google.com>
Date: Wed, 14 Feb 2024 12:30:49 -0800
Message-ID: <CAJuCfpEbdC4k=4aeEO=YfX2tZhkdOVaehAv9Ts7S42B_bmm=Ow@mail.gmail.com>
Subject: Re: [PATCH v3 00/35] Memory allocation profiling
To: Yosry Ahmed <yosryahmed@google.com>
Cc: Tim Chen <tim.c.chen@linux.intel.com>, akpm@linux-foundation.org, 
	kent.overstreet@linux.dev, mhocko@suse.com, vbabka@suse.cz, 
	hannes@cmpxchg.org, roman.gushchin@linux.dev, mgorman@suse.de, 
	dave@stgolabs.net, willy@infradead.org, liam.howlett@oracle.com, 
	corbet@lwn.net, void@manifault.com, peterz@infradead.org, 
	juri.lelli@redhat.com, catalin.marinas@arm.com, will@kernel.org, 
	arnd@arndb.de, tglx@linutronix.de, mingo@redhat.com, 
	dave.hansen@linux.intel.com, x86@kernel.org, peterx@redhat.com, 
	david@redhat.com, axboe@kernel.dk, mcgrof@kernel.org, masahiroy@kernel.org, 
	nathan@kernel.org, dennis@kernel.org, tj@kernel.org, muchun.song@linux.dev, 
	rppt@kernel.org, paulmck@kernel.org, pasha.tatashin@soleen.com, 
	yuzhao@google.com, dhowells@redhat.com, hughd@google.com, 
	andreyknvl@gmail.com, keescook@chromium.org, ndesaulniers@google.com, 
	vvvvvv@google.com, gregkh@linuxfoundation.org, ebiggers@google.com, 
	ytcoode@gmail.com, vincent.guittot@linaro.org, dietmar.eggemann@arm.com, 
	rostedt@goodmis.org, bsegall@google.com, bristot@redhat.com, 
	vschneid@redhat.com, cl@linux.com, penberg@kernel.org, iamjoonsoo.kim@lge.com, 
	42.hyeyoo@gmail.com, glider@google.com, elver@google.com, dvyukov@google.com, 
	shakeelb@google.com, songmuchun@bytedance.com, jbaron@akamai.com, 
	rientjes@google.com, minchan@google.com, kaleshsingh@google.com, 
	kernel-team@android.com, linux-doc@vger.kernel.org, 
	linux-kernel@vger.kernel.org, iommu@lists.linux.dev, 
	linux-arch@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, 
	linux-modules@vger.kernel.org, kasan-dev@googlegroups.com, 
	cgroups@vger.kernel.org
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable

On Wed, Feb 14, 2024 at 12:17=E2=80=AFPM Yosry Ahmed <yosryahmed@google.com=
> wrote:
>
> > > > Performance overhead:
> > > > To evaluate performance we implemented an in-kernel test executing
> > > > multiple get_free_page/free_page and kmalloc/kfree calls with alloc=
ation
> > > > sizes growing from 8 to 240 bytes with CPU frequency set to max and=
 CPU
> > > > affinity set to a specific CPU to minimize the noise. Below are res=
ults
> > > > from running the test on Ubuntu 22.04.2 LTS with 6.8.0-rc1 kernel o=
n
> > > > 56 core Intel Xeon:
> > > >
> > > >                         kmalloc                 pgalloc
> > > > (1 baseline)            6.764s                  16.902s
> > > > (2 default disabled)    6.793s (+0.43%)         17.007s (+0.62%)
> > > > (3 default enabled)     7.197s (+6.40%)         23.666s (+40.02%)
> > > > (4 runtime enabled)     7.405s (+9.48%)         23.901s (+41.41%)
> > > > (5 memcg)               13.388s (+97.94%)       48.460s (+186.71%)
> >
> > (6 default disabled+memcg)    13.332s (+97.10%)         48.105s (+184.6=
1%)
> > (7 default enabled+memcg)     13.446s (+98.78%)       54.963s (+225.18%=
)
>
> I think these numbers are very interesting for folks that already use
> memcg. Specifically, the difference between 6 & 7, which seems to be
> ~0.85% and ~14.25%. IIUC, this means that the extra overhead is
> relatively much lower if someone is already using memcgs.

Well, yes, percentage-wise it's much lower. If you look at the
absolute difference between 6 & 7 vs 2 & 3, it's quite close.

>
> >
> > (6) shows a bit better performance than (5) but it's probably noise. I
> > would expect them to be roughly the same. Hope this helps.
> >
> > > >
> > >
> > >